Push-pull electrical switch having reentrant shaped spring members



Nov. 9, 1965 w. SCHOTT ETAL 3,217,117

PUSH-PULL ELECTRICAL SWITCH HAVING REENTRANT SHAPED SPRING MEMBERS FiledMarch 9, 1962 WW I. II I a 5 I I I I I I m 37,904 E/VK, E; as 1?, $2155glans/v HTTOR VEZVJ' United States Patent 3,217,117 PUSH-PULL ELECTRICALSWITCH HAVING REENTRANT SHAPED SPRING MEMBERS Walter L. Schott, BeverlyHills, and James Irl Harvey,

Jr., Hollywood, Calif., assignors to International RectifierCorporation, El Segundo, Calif., a corporation of California Filed Mar.9, 1962, Ser. No. 178,720 2 Claims. (Cl. 20051.09)

This invention relates to a novel electrical switch and morespecifically relates to a push-pull type of switch of very inexpensiveconstruction, particularly adapted for use with educational kits and thelike.

A primary object of this invention is to provide a novel electricalswitch which is extremely inexpensive in construction and can beoperated by those having no experience with electrical equipment.

Another object of this invention is to provide a novel electrical switchwhich is simple to assemble and disassemble.

A further object of this invention is to provide a novel electricalswitch which is inexpensive in manufacture.

A still further object of this invention is to provide a novelelectrical switch which is inexpensive to manufacture and simple toinstall by those inexperienced in the electrical field.

These and other objects of this invention will become apparent from thefollowing description when taken in connection with the drawings, inwhich:

FIGURE 1 shows a side cross-sectional view of a switch built inaccordance with the present invention where the switch is in a closedposition.

FIGURE 2 is similar to FIGURE 1 and illustrates the switch in an openposition.

FIGURE 3 is an exploded perspective diagram showing the operatingplunger contact springs and support panel for the switch of FIGURES 1and 2.

Referring now to the figures, we have illustrated therein a switchparticularly applicable for use with educational kits and which servesas a push-pull type of switch.

The switch is more specifically formed of a support board of insulationmaterial which has square openings such as opening 11 of FIGURE 3therein. The opening 11 receives the elongated section 12 of anoperating plunger 13. The operating plunger 13 is a unitary member andincludes a necked down portion 15 which terminates in an enlarged platesurface 16.

The switch contacts are then formed of spring clips 17 and 18 which canbe formed from a fiat strip brass. The brass stock used for forming theclips for contact arms 17 and 18 may, for example, have a thickness of0.016 inch, a width of 0.200 inch and a length of 1.60 inches.

The clips 17 and 18 are generally shaped with extending contact portions19 and 20 respectively, at their upper ends. Clips 17 and 18 may besecured to extending portions 21 and 22 of the panel 10 by screws suchas wood screws 23 and 24 which pass through pre-formed openings in thelower legs of clips 17 and 18 and then into portions 21 and 22.

When installed in this manner, the spring clips will normally have theircontact portions 19 and 20 in relatively high pressure contactengagement.

The plunger 13 is then assembled by passing the elongated section 12through openings such as opening 11 and pushing the head plate 16 of theplunger 13 through opposing reentrant sections 25 and 26 of springs 17and 18, causing the springs 17 and 18 to open until necked-down portion15 of plunger 13 is placed adjacent sections 25 and 26. The necked-downportion 15 has a sufiiciently small diameter to permit contact portions19 and 20 to be closed as illustrated in FIGURE 1.

3,Zl7,ll 7 Patented Nov. 9, 1965 In order to open the switch, it is onlynecessary to pull section 14 of plunger 13 outwardly to move the plungerdownwardly and bring the larger diameter portion adjacent necked-downregion 15 adjacent reentrant sections 25 and 26 of spring clips 17 and18 respectively. This will, as shown in FIGURE 2, bias springs 17 and 18away from one another to open the contact at contacting portions 19 and20.

In operation, it will be apparent that an electrical circuit can beconnected to the spring clips 17 and 18, for example, by using screws 23and 24 as terminal members. The switch is a push-pull switch which is inthe engaged position when the plunger 13 is in, as shown in FIGURE 1,the disengaged position when the plunger is out as shown in FIGURE 2.The plunger is retained within clips 17 and 18 by the locking of plate16 and reentrant portions 25 and 26.

In order to disassemble the switch, the contact springs 17 and 18 can bespread by hand until plate 16 clears reentrant portions 25 and 26.

Although we have described preferred embodiments of our novel invention,many variations and modifications will now be obvious to those skilledin the art, and we prefer therefore to be limited not by the specificdisclosure herein but only by the appended claims.

The embodiments of the invention in which an exclusive privilege orproperty is claimed are defined as follows:

1. An integral electrical switch comprising a base, an operatingplunger, and a pair of conductive spring members; one end of each ofsaid spring members being secured to said base; the opposite end of eachof said spring members being normally in engagement with one another;each of said spring members having a centrally located reentrant shapedportion; said plunger extending through said base and having a firstportion adjacent said reentrant shaped portions of said spring membersand a second portion on the side of said base opposing said sidereceiving said spring members; said portion of said plunger adjacentsaid reentrant shaped portions having a necked down region defined by asmall diameter portion axially interposed between adjacent relativelylarge diameter portions of said plunger; said plunger being axiallymovable between a first position and a second position to interpose asmall diameter portion or large diameter portion respectively of saidnecked down region between said reentrant shaped portions of said springmembers; said opposite end of each of said spring members being engagedwhen said plunger is in said first position; said opposite end of eachof said spring members being disengaged when said plunger is in saidsecond position; said reentrant shaped portion of each of said springmembers spaced from the contacting end of their said respective springmembers and intermediate the ends of their said respective springmembers.

2. An integral electrical switch comprising a base, an operatingplunger, and a pair of conductive spring members; one end of each ofsaid spring members being secured to said base; the opposite end of eachof said spring members being normally in engagement with one another;each of said spring members having a centrally located reentrant shapedportion; said plunger extending through said base and having a firstportion adjacent said reentrant shaped portions of said spring membersand a second portion on the side of said base opposing said sidereceiving said spring members; said portion of said plunger adjacentsaid reentrant shaped portions having a necked down region defined by asmall diameter portion axially interposed between adjacent relativelylarge diameter portions of said plunger; said plunger being axiallymovable between a first position and a second position to interpose asmall diameter portion or large diameter portion respectively of saidnecked down region between said reentrant shaped portions of said springmembers; said opposite end of each of said spring members being engagedwhen said plunger is in said first position; said opposite end of'eachof said spring members being disengaged when said plunger is in saidsecond position; said reentrant shaped portion of each of said springmembers spaced from the contacting end of their said respective springmembers and intermediate the ends of their said respective springmembers; the end of said plunger adjacent said necked down portion beingenlarged whereby said plunger is trapped by said reentrant shapedportions of said spring members.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS10/35 Germany.

BERNARD A. GILHEANY, Primary Examiner. ROBERT K. SCHAEFER, Examiner.

1. AN INTEGRAL ELECTRICAL SWITCH COMPRISING A BASE, AN OPERATINGPLUNGER, AND A PAIR OF CONDUCTIVE SPRING MEMBERS; ONE END OF EACH OFSAID SPRING MEMBERS BEING SECURED TO SAID BASE; THE OPPOSITE END OF EACHOF SAID SPRING MEMBERS BEING NORMALLY IN ENGAGEMENT WITH ONE ANOTHER;EACH OF SAID SPRING MEMBERS HAVING A CENTRAL LOCATED REENTRANT SHAPEDPORTION; SAID PLUNGER EXTENDING THROUGH SAID BASE AND HAVING A FIRSTPORTION ADJACENT SAID REENTRANT SHAPED PORTIONS OF SAID SPRING MEMBERSAND A SECOND PORTION ON THE SIDE OF SAID BASE OPPOSING SAID SIDERECEIVING SAID SPRING MEMBERS; SAID PORTION OF SAID PLUNGER ADJACENTSAID REENTRANT SHAPED PORTIONS HAVING A NECKED DOWN REGION DEFINED BY ASMALL DIAMETER PORTION AXIALLY INTERPOSED BETWEEN ADJACENT RELATIVELYLARGE DIAMETER PORTIONS OF SAID PLUNGER; SAID PLUNGER BEING AXIALLYMOVABLE BETWEEN A FIRST POSITION AND A SECOND POSITION TO INTERPOSE ASMALL DIAMETER PORTION OR LARGE DIAMETER PORTION RESPECTIVELY OF SAIDNECKED DOWN REGION BETWEEN SAID REENTRANT SHAPED PORTIONS OF SAID SPRINGMEMBERS; SAID OPPOSITE END OF EACH OF SAID SPRING MEMBERS BEING ENGAGEDWHEN SAID PLUNGER IS IN SAID FIRST POSITION; AND OPPOSITE END OF EACH OFSAID SPRING MEMBERS BEING DISENGAGED WHEN SAID PLUNGER IS IN SAID SECONDPOSITION; SAID REENTRANT SHAPED PORTION OF EACH OF SAID SPRING MEMBERSSPACED FROM THE CONTACTING END OF THEIR SAID RESPECTIVE SPRING MEMBERSAND INTERMEDIATE THE ENDS OF THEIR SAID RESPECTIVE SPRING MEMBERS.